Lesson 3 - Get funded - can't compile using SafeMath.sol

[DorianDaSilva]

Hi,

I have been following along without issue until now. My remixID compiler is returning an error for the import "@chainlink/contracts/src/v0.6/vendor/SafeMathChainLink.sol";

It returns: "not found @chainlink/contracts/src/v0.6/vendor/SafeMathChainLink.sol".

I get the error even when I try to import safeMath from OpenZeppelein or any other repot. Is this related to the prgama declaration or version being used? Can someone please share instructions on how to fix this issue?

Thank you

[Noveleader]

Hey, this is mostly due to Solidity versions keep them aligned in each file. You can access Chainlink and SafeMath and change solidity versions according to what's in your own smart contract. But also if this doesn't work also keep an eye on which contract you are deploying.

[Noveleader]

Hey @DorianDaSilva replace SafeMath import to this
import "@chainlink/contracts/src/v0.6/vendor/SafeMathChainlink.sol";
This is deploying for me after replacing it properly I guess you wrote it wrong. Check this is working for me now.

Full code is :

//SPDX-License-Identifier: MIT
pragma solidity >=0.6.6 <0.9.0;

import "@chainlink/contracts/src/v0.6/interfaces/AggregatorV3Interface.sol"; 
import "@chainlink/contracts/src/v0.6/vendor/SafeMathChainlink.sol";


contract FundMe {
    using SafeMathChainlink for uint256;


//To keep track of who send us funds create mapping between addresses and value (uint256=value)
    mapping(address => uint256) public addressToAmountFunded;
    address[] public funders;
    address public owner;

    constructor(){
        owner = msg.sender;
    }

    function fund() public payable {
        //Set threshold for minimum 50$ transaction = min value * 10 raise the 18 so everything has 18 decimals
        uint256 minimumUSD = 50 * 10 ** 18;
        require(getConversionRate(msg.value) >= minimumUSD, "You need to spend more ETH!");

        // keep track of all the people that send us value
        addressToAmountFunded[msg.sender] += msg.value;
        //what the ETH -> USD conversion rate
        //Decentralized oracle network chainlink
        //we have to tell Solidity what functions can be called on another contract 
        funders.push(msg.sender);
    } 
    //public view because we will be reading
    function getVersion() public view returns (uint256){

        //Define working with other contracts or interfaces
        //name the type - name the visibility = initialize the contract
        //locate where address where contract is located 
        //look at the ethereum price feed for the desired network in Chainlink data feed ethereum docs
        AggregatorV3Interface priceFeed = AggregatorV3Interface(0x8A753747A1Fa494EC906cE90E9f37563A8AF630e);
        return priceFeed.version();
    }

    function getPrice() public view returns(uint256){
        AggregatorV3Interface priceFeed = AggregatorV3Interface(0x8A753747A1Fa494EC906cE90E9f37563A8AF630e);
        (,int256 answer,,,) = priceFeed.latestRoundData();
        
        //Add uint256 and wrap it around answer to type cast and convert it into the expected type uint256
        
        return uint256(answer * 10000000000);
        //ETH = 3,1466.8000000 USD
    }

    function getConversionRate(uint256 ethAmount) public view returns (uint256){
        uint256 ethPrice = getPrice();
        uint256 ethAmountInUsd = (ethPrice * ethAmount) / 1000000000000000000;
        return ethAmountInUsd;
        //0.000003124414383370 USD
    }

    modifier onlyOwner{
        require(msg.sender == owner);
        _;
    }



    function withdraw() payable onlyOwner public {

        //who ever calls the withdrawl function (msg.sender) transfer them all of the money (balance)
        //We only want the contract admin/owner to be able to withdraw

        payable(msg.sender).transfer(address(this).balance);
        for (uint256 funderIndex=0; funderIndex < funders.length; funderIndex++){
            //index var starts at 0 , loop finsihes whenever funder index is < funders length, everytime we finish a loop we add 1 to the funder index
            address funder = funders[funderIndex];
            addressToAmountFunded[funder] = 0;
        }
        funders = new address[](0);
    }   
}

[cromewar]

Again @Noveleader is right, you have commented your SafeMath import.

[Noveleader]

Again @Noveleader is right, you have commented your SafeMath import.

And onto that SafeMathChainlink had a capital L in it which caused the whole problem initially.

[DorianDaSilva]

@Noveleader Thank you so much, it seems you were right. It was a simple synthax error on Chainlink. Help very much appreciated.

[Noveleader]

@DorianDaSilva nice you got your help, I should have figured it out before but when you sent your full code I tried deploying it also. Also, check out this cause I can see you are going to get into this trouble.